Effect of deformation on the parameters of solid-solid phase transitions in polytetrafluoroethylene

A. K. Borisov^a, V. M. Egorov^a, V. A. Marikhin^a, L. P. Myasnikova^a, S. A. Tsygankov<sup>b

a</sup> Ioffe Institute, St. Petersburg, Russia
^b "Formoplast" LLC, St. Petersburg, Russia

Abstract: The influence of hydroextrusion and orientation drawing on the parameters of solid-solid phase transitions in polytetrafluoroethylene has been studied by differential scanning calorimetry. A comparative analysis of the heat capacity peaks based on the theory of diffuse first-order phase transitions showed a significant increase in the period of the macromolecular helix from the nano-level in the original polymer to the micro-level in the oriented one. In the latter, the effect of the formation of a “superhelix” was found. An assumption was made about the mechanism for the supermolecular structure transformation leading to the observed effect.

Keywords: phase transition, polytetrafluoroethylene, supermolecular structure, hydroextrusion, orientation drawing, differential scanning calorimetry.

Received: 11.07.2023
Revised: 30.08.2023
Accepted: 07.09.2023

DOI: 10.61011/PJTF.2023.20.56344.19682

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